Method for manufacturing printed circuit board

Abstract

A method for manufacturing a printed circuit board according to one embodiment of the present invention includes a step of forming a resist pattern, and a step of forming a conductive pattern by using the resist pattern. The resist pattern has an acute angle portion in which an outer edge of a resist is bent to form an acute angle in a plan view. In a corner portion of the acute angle portion, an outer-side outer edge of the resist is rounded, and a radius of curvature of the outer-side outer edge is more than or equal to a distance from the outer-side outer edge to another outer edge adjacent thereto in a direction away from a center of curvature of the outer-side outer edge.

The invention claimed is: 
     
       1. A method for manufacturing a printed circuit board, comprising a step of forming a resist pattern from a resist, and a step of forming a conductive pattern by performing selective plating or etching by using the resist pattern,
 wherein the resist pattern has an acute angle portion in which an outer edge of the resist is bent to form an acute angle in a plan view, 
 in a corner portion of the acute angle portion, an outer-side outer edge of the resist is rounded, and a radius of curvature of the outer-side outer edge is more than or equal to a distance from the outer-side outer edge to another outer edge adjacent thereto in a direction away from a center of curvature of the outer-side outer edge, and 
 an average thickness of the resist is 15 μm or more and 100 μm or less. 
 
     
     
       2. The method for manufacturing a printed circuit board according to  claim 1 , wherein the resist pattern has a linear opening, and
 a maximum width of the linear opening is less than or equal to 1.2 times an average width of wires in the conductive pattern. 
 
     
     
       3. The method for manufacturing a printed circuit board according to  claim 1 , wherein the resist pattern has three or more linear openings and an annular opening, and
 the three or more linear openings are connected via the annular opening. 
 
     
     
       4. The method for manufacturing a printed circuit board according to  claim 1 , wherein, in the corner portion of the acute angle portion, a width of the resist having the outer-side outer edge in a direction of the radius of curvature is more than or equal to the distance from the outer-side outer edge to the other outer edge. 
     
     
       5. The method for manufacturing a printed circuit board according to  claim 1 , wherein the resist is a dry film photoresist. 
     
     
       6. A method for manufacturing a printed circuit board, comprising a step of forming a resist pattern from a resist, and a step of forming a conductive pattern by performing selective plating or etching by using the resist pattern,
 wherein the resist pattern has three or more linear openings and an annular opening, 
 the three or more linear openings are connected via the annular opening, and 
 an average thickness of the resist is 15 μm or more and 100 μm or less.